JavaScript retrieve and replace string parts in stringified JSON [duplicate]

Question

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Parse JSON in JavaScript? [duplicate] (16 answers)

Closed 9 years ago.

I have a string compared to this:

{
    "objects": [{
        "originY": "top",
        "left": 0,
        "top": 0,
        "width": 118.33,
        "height": 100,
        "name": 1
    }, {
        "originY": "top",
        "left": 0,
        "top": 0,
        "width": 118.33,
        "height": 100,
        "name": 2
    }],
    "background": ""
}

I need to loop to this string and retrieve the values of left, top, width and height and multiply them by a factor and then save them as a new string again.

Any idea of how I could accomplish this?

Answer 1

Because the string is JSON, the easiest way to handle the data is to parse it into an array of objects, update the values, then output it as a string again.

// Parse
var container = JSON.parse(yourString);

// Get and update
var i, len, top, left, width, height;
len = container.objects.length;
for (i = 0; i < len; i++) {
    top = container.objects[i].top;
    left = container.objects[i].left;
    height= container.objects[i].height;
    width = container.objects[i].width;
    // * Save top, left, width somewhere. *
    // Multiply by some factor.
    container.objects[i].top *= factor;
    container.objects[i].left *= factor;
    container.objects[i].height *= factor;
    container.objects[i].width *= factor;
}

// Convert to string again.
theString = JSON.stringify(container);

Answer 2

You can assign the json to a variable and then iterate it and do what ever you want

        var koko = {
            "objects": [{
                "originY": "top",
                "left": 1,
                "top": 0,
                "width": 118.33,
                "height": 100,
                "name": 1
            }, {
                "originY": "top",
                "left": 2,
                "top": 0,
                "width": 118.33,
                "height": 100,
                "name": 2
            }],
            "background": ""
        }



        for(var i=0;i<koko.objects.length;i++) { koko.objects[i].left = 10; }